I looked up 'dóthanach' in FGB. It's not suitable here. Check it out and you'll see what I mean.

With "de" it has a negative connotation. It should be alright by itself. In the same dictionary, "Is leor sin" which seems to be that pattern for which you get your sentence, is paired with "ní beag sin!" and seems to connote "That's enough!" I'm not sure that would work although I don't know 100%. I think we need more input on this.

In the same dictionary, "Is leor sin" which seems to be that pattern for which you get your sentence, is paired with "ní beag sin!" and seems to connote "That's enough!" I'm not sure that would work although I don't know 100%. I think we need more input on this.